A wealthy aristocrat posed as freelance journalist called Caroline as she fled the authorities with her partner and their secret newborn baby, a retrial heard.
Jurors at the Old Bailey were told Constance Marten, 37, used the ruse as she checked in to a service station hotel at 4am while on the run with Mark Gordon, 50, and their daughter Victoria in January 2023.
The parents deny gross negligence manslaughter and causing or allowing the death of the infant, whose birth they concealed to stop her from being taken into care like their four other children.
Victoria died of hypothermia or suffocation after they took her “off-grid” in a flimsy tent on the South Downs in winter, it is alleged.
In a statement read to the jury on Wednesday, receptionist Cathy Lloyd said Marten seemed "really sweet" and “genuine” as she checked in to the Ibis Hotel at Lymm Services in Warrington on 4 January 2023.
She claimed she was a freelance journalist called Caroline Marten and asked to pay for the room in cash as she had lost her credit card, Ms Loyd said.
The day before Marten had received £3,400 into her bank account from a trust fund, the court was told.
The receptionist said the defendant had seemed "extremely well-spoken" and "genuine", but "very tired", adding: "Constance made conversation with me and was very sweet and conversational.
"She told me she was very tired after driving 'a hell of a long way'. She told me she had lost her credit card and if she could pay cash. She told me she lived in Hackney and just wanted to go home."
Having told her she was a freelance journalist, Marten chatted with Ms Lloyd about publicity for her brother who was in a play, jurors heard. Ms Lloyd handed over her email address and phone number, but never heard back from Marten.
Gordon entered reception shortly after Marten had gone to her room but appeared to be "very moody" and did not reply to the receptionist’s inquiry about whether he had checked in, which she found "unnerving", jurors heard.
Ms Lloyd said: "I really thought she was a journalist. At no time did I see Constance and Mark together. At no point did I see a baby with either of them.
"I definitely did not see a baby or any baby items. None of their body language indicated they had a baby with them."
The following day the couple abandoned their belongings at the side of the M61 near Bolton, Greater Manchester, after their Peugeot burst into flames.
Ken Hudson filmed the fire on the motorway and called emergency services at 6.19pm, but the couple fled on foot before police arrived.
He told jurors that he saw a female passenger holding a bundle with a baby's head with wispy hair showing.
Giving evidence in court, Mr Hudson said he had asked her "is the baby alright", and she replied: "She's fine."
He touched the baby's head and said "God bless", he said.
Police launched a nationwide manhunt after they discovered a placenta wrapped in a towel in the burnt out wreckage.
The couple are accused of “recklessly” taking the infant on the run as they travelled the country by taxi before settling in a “flimsy” tent on the South Downs.
Victoria’s decomposing body was eventually found by the police stashed in a Lidl bag-for-life, which they allegedly also used to carry her around while on the run.
Marten and Gordon both deny charges of gross negligence manslaughter of Victoria and causing or allowing the infant’s death.
The jury heard that last year that the pair was convicted of concealing the birth of the child and perverting the course of justice in a previous trial.
The retrial continues.
